Science is different from other subjects because it uses experiments to test ideas.

BRANCHES OF SCIENCE

Biology - the study of all living things and their surroundings

Microbiology - the study of micro-organisms

Botany - the study of plants

Zoology - the study of animals

Chemistry - the study of the composition of substances and their effects upon each other

Physics - the study of the natural laws and properties of matter and energy that is not confined to living things (e.g. light, sound, heat)

Astronomy - the study of stars planets and other celestial bodies, their movements, relative positions and compositions

Geology - the study of the earth and its origin, structure and composition

Meteorology - the study of the weather

Palaeontology - the study of fossils

Seismology - the study of earthquakes

Vulcanology - the study of volcanoes

WHAT DOES A SCIENTIST DO?

A scientist must be able to study facts, collect and organise information, reach conclusions and make hypotheses.

Subjective - Subjective observations are based on personal opinions (e.g. That chocolate was very tasty; The water was chilly). These are too inaccurate to be used by scientists because different people have different opinions.

Objective - Objective observations are those based on accurate measurements (e.g. a ruler is 30cm long; Water boils at 100oC). Scientists try to use objective measurements as often as possible.

Hypothesis - An hypothesis is a prediction or idea to be tested by experiment (e.g. When an object is heated, it gets larger.)

Observation - Observations use our senses such as eyesight, hearing and touch. Observations are what we see, hear or feel and should be objective as much as possible, and data should be recorded (e.g. At 20oC, the metal strip was 20cm long and at 50oC, the same metal strip was 34cm long)

Data - Data is the information that may be recorded in tables, graphs, diagrams or sentences. All tables, graphs and diagrams should be clearly labelled.

Inference - An inference is an explanation of why an occurrence happened (e.g. Hot objects have more heat energy and therefore the particles in the object are able to move further apart, and that is why a hot object expands)

Variable - Variables are factors that change or vary in an experiments (e.g In an experiment to grow plants, some of the variables are the type of plant, the amount of sunlight, the amount of water, the temperature, the amount of soil, the type of soil and so on).

In experiments, all except one variable must be kept the same. The one variable that changes is the one being tested (e.g. In an experiment to test the effect of sunlight on plant growth, a scientist would use the same plants, the same pots, the same soil, the same amount of water and so on. The only factor allowed to change would be the amount of sunlight.)

Control - The control experiment is the one to which the rest of the experiment is compared. This is done to show the effect of one factor in the experiment (e.g. In an experiment to test the effect of sunlight on plant growth, a scientist would have two groups of plants that were treated in the exactly the same way except for one thing - one group would be exposed to a short period of sunlight (control) and the other group would be exposed to a longer period of sunlight.)

THE SCIENTIFIC METHOD

Scientists use the following method to investigate things:

Make Observations - A scientist sees something happening which he/she does not understand.

Form an Hypothesis - An hypothesis is a general statement, which gives a possible answer to a question or problem. An hypothesis can be tested by experiment.

Test an Hypothesis - A scientist tests the hypothesis by designing and carrying out an experiment.

Collect Data or Information - Objective data or information is collected and recorded during the experiment.

Draw a Conclusion - A scientist uses the information to prove or disprove the hypothesis.

Communicate the Findings - He/she would then pass on the results and conclusions of the experiment to other scientists through journals, magasines or the internet. Scientists use internationally recognised symbols to communicate with other scientists around the world.